Supracrestal implant placement improves peri-implant health in T2DM patients: A randomized clinical trial

This study, designed as a randomized controlled trial, investigated how the vertical placement of implants influences peri‑implant conditions in patients with type 2 diabetes mellitus (T2DM) treated with mandibular overdentures.

Twenty-two edentulous individuals with T2DM received two implants each in the anterior mandible following a split-mouth design: one placed at the crestal level (CL) and the other at a supracrestal level (SL). Clinical, immunoenzymatic, and tomographic assessments were conducted at prosthesis placement (baseline) and after 6, 12, and 24 months.

Probing depth (PD) and clinical attachment level (CAL) were consistently higher in CL group than SL in all evaluated periods (p < 0.05). Immunoenzymatic assay showed that CL implants demonstrated higher concentrations of IL-4, at 6, 12 and 24 months, and IL-21 at 24 months, when compared to SL implants (p < 0.05). Radiographically, the bone loss was similar in both groups (p > 0.05). Higher bone loss was detected in the first year of implant loading compared to the second year in both SL and CL group (p < 0.05). In the SL group, the mean bone loss increased by 31.22 % from baseline to 24 months, corresponding to a change of 0.74 mm. In the CL group, the initial variation was 1.21 mm (69.94 %) over the same period.

These findings suggest that supracrestal implant placement may offer clinical and immunoinflammatory advantages in patients with T2DM, promoting better peri‑implant health and reduced bone loss over time. Within the limitations of this study, SL positioning appears to be a favorable strategy for implant-retained overdentures in diabetic individuals. The clinical trial registry number is NCT03988140.

Rehabilitating diabetic patients with dental implants can be challenging. This study demonstrates that supracrestally placed dental implants exhibit better clinical behavior in maintaining peri‑implant health.